Part 1: Can Vaccines be 90% Effective at Reducing Deaths?

Looking at the implications of VE and vaccinated population

I continue to be unable to reconcile the claim that vaccines are 90%+ effective at reducing deaths with the actual number of COVID deaths we have experienced this summer in the US. I plan to do two posts (ha! probably more, this rabbit hole is fascinating) on this. In each, I will start with the premise that vaccines are 90% effective against death and discuss what that should imply for the pandemic. In this post, I will walk through what one might estimate the deaths would look like at this point of the pandemic given that presumed vaccine efficiency (VE) and the vaccinated rates of the population.

Let’s start by providing the summary information on 2020 COVID deaths by age group:

Sources: Population from US Census data; Deaths from CDC

Although I would argue it is often understated, most folks acknowledge the extreme skew in deaths towards the older groups, but this is very important when thinking through how vaccines should have impacted current deaths.

Next, I sought data on the % of population of folks who have been fully vaccinated in each age group. Typical of many of the government statistics, they helpfully use different age categories for this data:

Sources: CDC

Since the age categories do not match, I will attempt to be conservative and use the smaller number where applicable. For example, for the 35-44 age group, we would expect the vaccination rate to be between 58 % (25-39 years) and 66.7% (40-49 years). I will be conservative and assume the smaller number of 58%. Now, to estimate how many deaths we would expect to be reduced via the vaccine, we simply multiply the percentage of people fully vaccinated by the assumed VE (90%). So, for example, we would expect the deaths of 75+ year old’s to be reduced by 81% * 90%= 73%. With that logic, we can estimate what the 2020 total deaths would have looked like with this level of vaccination:

What’s important here is not the specific number projected, but the number relative to last year where 0 people were vaccinated. Namely, if vaccines were preventing death at 90% and we have this many folks fully vaccinated (importantly, very high rates at the ages where most deaths occur), we should expect deaths to be only 28% (101K/362K) of what they would be in an unvaxxed world.

So, let’s compare the deaths in the July-Oct months in 2020 vs. 2021:

In July, we see 2021 deaths are 34% of deaths in 2020, not too far from what we expected. In August 2021, they are 90% of 2020; September deaths in 2021 are 2.5x what they were in 2020 and October 2021 already has more deaths than 2020 and we only have numbers through the 15th. Something is deeply wrong here.

Now, folks might say that in 2021 we are dealing with Delta which wasn’t around in 2020. The evidence I have seen does not indicate that Delta is particularly more infectious, or deadly but I won’t go into that here. Nevertheless, I’d ask people to think about this. If vaccines are at 90% efficiency, then given the numbers we are seeing, that would imply we would have had 55,412/0.28 = 197,900 deaths this September if no one was vaccinated! This is more than 2x the worst month of the pandemic, January 2021. Does anyone think that is plausible? Why?

Note, I believe everything I have done is conservative. I have used the lower bound of vaccine rates for each age group and I have ignored several additional reasons we should have expected 2021 to be better than 2020:

• Natural immunity- way more people have already had COVID by summer of 2021 and should have natural immunity and not be dying.

• Stronger stock- Sadly, the natural assumption is that COVID would have caused the deaths of many of our most vulnerable 1st. The population that had not been killed by COVID by summer 2021 should generally be healthier.

• Better treatments- A lot more is known about treating the sick and death rates should in general be lower in 2021 vs 2020.

I promise you, I want to be wrong. I want vaccines to be 90% effective. Please show me where I have made an error or are missing something. This whole train of thought takes me back to my graduate school days where I would do a lot of “proofs by contradiction” … if we assume A is true, then that implies B… but B we know is false, so therefore A must be false. In this case, if vaccines are 90% effective against death, that would imply an unvaccinated September 2021 would have been 2x worse than any previous month during the pandemic. I find that nearly impossible to believe and therefore can’t believe the 90% VE.